Tricone Bit/Roller Cone Bit 8 1/2 Inch IADC 517 -637 for Hard Formation Well Drilling

China Tricone Bit/Roller Cone Bit 8 1/2 Inch IADC 517-637 for Hard Formation Well Drilling, Find details about China Tricone Bit, TCI Tricone Bit from Tricone Bit/Roller Cone Bit 8 1/2 Inch IADC 517-637 for Hard Formation Well Drilling